It is known to grow plants in ceramic pots or pots of synthetic plastic material, wherein the pots have wall surfaces disposed parallel to one another. The roots of the plants can then extend into the earth in the pot or to another substrate placed in the pot for receiving the roots. There are also known hydro-culture processes in which the roots in general are maintained in substrates free of any nutrients, such as, for example, expanded clay, grain, or granulates from perlite, sand or the like, and wherein the nutrients are supplied in precisely measured form as a result of lack of any buffer effect. A pot containing the substrate with the plant is then set into a container partially filled with water, so that the roots penetrate the bottom of the pot which is provided with openings and project into the water (see for example Swiss Pat. No. 284,290, or U.S. Pat. No. 4,106,235).
From German laid-open patent specification No. 2,059,748, it is also known to cultivate cuttings for reproduction of suitable plants, for example bushes, shrubs, trees or hydro-culture plants, in a container which, for example has parallel inner wall portions. Here the plant is inserted by means of root-receiving means, made, for example of foam, into a container for hydro-culture filled partially with water, so that the roots project from the root-receiving means into the water. After a suitable time the root-receiving means can be transplanted from the container the hydro-culture into the earth.
These processes suffer from the disadvantage however, that the insertion of the container for hydro culture requires a substrate or a container for the substrate, which encloses the roots of the plant. Prior to planting the plant in the earth, the roots must be freed from the substrate, or the roots must be cleared, for example by plucking the substrate apart, which may injure the roots. It is also necessary during the transplant operation to remove the container for the substrate, so that the roots may pass immediately into the earth, which is also a costly operation which generates a lot of dirt.
It is also known to induce cuttings for the reproduction of suitable plants in a container, which is partially filled with water, to generate roots, such that the cuttings standing on the floor or bottom of the container are maintained generally loose with respect to one another, so that following generation of roots, a transplant in a desired substrate may be accomplished.
Finally there are known processes for restricting plant growth, which act particularly on the root system, for example the known Bonsai culture. Here the space for the roots is purposely limited, and the roots as well as the surface portion of the plant are cut, or as in another known process, the space available for the roots is limited to a very fine perforated funnel-shaped metal insert within a normal earth portion. In a Bonsai process for growing woody plants for example, shrubs, trees, bushes and the like, as is known a flat container, a so-called Bonsai container is used, which contains a plant substrate, namely earth, which is intended to limit the space for the roots. In the initial stage even, for example an orange peel can serve as a container, through which the roots can grow. Later the plant can be transplanted into a Bonsai container. In order to limit growth, the roots as well as the surface portion of the plant are cut from time to time, in order to attain an artful dwarf-like or crippled form of growth of the plant ("Mein Garten im Hause" Hoffman and CampeVerlag, Hamburg, Federal Republic of Germany, 1976, Pages 178 to 186, or Roger Grounds "So pflegtman Zimmerpflanzen", Verlag Paul Barey Berlin and Hamburg, Federal Republic of Germany, 1978, Pages 42 to 49; or V. Dietiker, "Bonsai Japanische Zwergbaumeals Hobby", Hallwag-Verlag Bern, Switzerland, 1980.)
So that the roots can be cut, they must however first of all be freed from earth avoiding any damage to the roots, which is costly and generates a lot of dirt. As is known it is also necessary that a sufficient number of fine hair-like roots are disposed densely around the main stem, for if the relatively stronger roots were to be cut, the plant would suffer damage, which could lead to the death of the plant. Furthermore care must be taken in uprooting the plant, to avoid any damage to the roots. Finally there is also known a growth process of plants from limited plant cells, the so-called Meristem culture. This process must be initiated within a closed container, for example a sterile glass container under extremely hygienic conditions. This Meristem culture is accomplished in a special gel suitable for plants, which contains exactly measured traces of the required nutrients and trace elements, as well as growth inhibitors. The miniature plants developed therefrom have been made available in commerce in such reaction containers and using the special gel, in a manner so that the miniature plants "float" on the gel, and abut the wall of the container when growing. This costly method, has not, however been successful, as the growth of the plant can to all intents and purposes not be influenced, and because the very sensitive miniature plants die easily, certainly during any attempt to transplant them, due to the many bacteria and other damage-causing factors contained in the surrounding atmosphere, to which the miniature plants are not accustomed.